This invention relates generally to crop harvesting and threshing machines, more commonly known as combines, and more particularly to the type of combine commonly referred to as an axial flow type of combine. The axial flow type of combine is characterized by having the crop material pass axially through an elongate housing which has a separate casing therein that surrounds each threshing and separating apparatus or rotor. The crop material is passed spirally rearward about the rotors contained within each casing. Specifically, the invention is concerned with providing a structure that is easily removed from the side frame of the combine to permit quick and convenient access to the rotor area. This access unit or rotor access module permits the operator to service the rotor and its underlying concaves in a minimum of time and without the need for any special tools or assistance. This invention is equally applicable to an axial flow type of combine utilizing either a single threshing or separating rotor, multiple threshing and separating rotors, or any comparable apparatus utilized for rotary threshing and separation.
Conventional combines pass the crop material to be threshed between a rotary cylinder and a stationary concave in a direction that is normal to the axis of the rotating cylinder and parallel with the longitudinal axis of the combine frame. In this system much of the grain contained in the crop material fed to the cylinder and the concave passes through the concave as threshed grain. The remainder of the material is conveyed to separating elements of the combine that traditionally include reciprocating or oscillating straw walkers, grain pans and chaffer sieves. Because of the combined effect of the transverse orientation of the rotary cylinder and the single pass of crop material about the cylinder during threshing, there is less of an urgent need to have convenient and rapid access to the threshing area. Since the threshing concave and cylinder extends transversely across the width of a conventional combine, access at one particular relatively narrow point in either side or both sides of the combine permits servicing of the entire width of the concave and threshing cylinder.
Combines of the axial flow type, in contrast, utilize single or dual threshing and separating apparatus, such as rotors, that permit the crop material to pass over the concave during the threshing process three or more times. The concaves run from front to rear and generally underlie a single or dual rotor system that is parallel to the longitudinal axis of the combine. This longer area of contact between the rotors and the concaves of necessity requires a larger access area for the operator when servicing the rotors and the concaves.
This need for convenient access to the rotor and concave area in the relatively recently commercially developed axial flow types of combines was early recognized by the designers of these machines. Relatively elongated access plates were provided on the sides of the frames of some of these early axial flow type of combines to permit a substantial portion of the threshing area to be serviced at one time. However, simply having access to the threshing and separating area of the axial flow combines did not solve the entire problem since the concaves still had to be serviced in a restricted area, as well as having to be removed in order to reach the rotor.
Different approaches were attempted to provide easily removable concave sections underlying the threshing portion of the rotors. One of these early approaches requires that the header and infeed housing mounted to the front portion of the combine be removed entirely from the combine base unit before the concave sections are slid forwardly out of their mountings. Another approach involves the utilization of linkages which permit the forward portion of the concave to be pivoted toward the side of the machine to remove it from the rotor casing. This solved the problem of providing an easy way to change the wire inserts in the concave sections, but did little to improve accessibility to the rotor and the remaining portions of the concaves. None of the aforementioned approaches provided a technique that would permit easy access to the rotor and the remaining concaves for servicing. Additionally, when concave extensions were utilized the separate fasteners utilized to hold them in place in the rotor casings had the potential to come loose and fall out or merely fail because of the high level of vibrational activity in the area surrounding the rotating rotors.
The foregoing problems are solved with the design of the machine comprising the present invention by providing a rotor access module that is removably insertable through the frame of a combine into the rotor casing with an interior portion that cooperates with the existing concaves as an integral part of the rotor casing during the threshing and separating cycle when it is fully inserted and when removed from the casing and the frame provides easy access to the rotor and concaves for servicing.